Pritzker accused Rauner of being slow to act after he learned a suburban Chicago company where he once had a business interest was emitting cancer-causing gas, and of covering up a deadly Legionnaires’ disease outbreak at a western Illinois veterans’ home.

“For three years he failed to protect them,” Pritzker said. “Fourteen people died.”

The candidates met for their first two-way debate as polls show Pritzker with a sizable lead over the first-term incumbent . The gubernatorial race pits Rauner, a multimillionaire former businessman, against Pritzker, the billionaire heir to the Hyatt hotel fortune. Together they’ve put roughly $200 million into their campaigns, and the contest could set a new record for spending in a U.S. governor’s race.

Wednesday’s debate at ABC7 Chicago started shortly after a spokeswoman for Democratic Attorney General Lisa Madigan said the office has launched a criminal investigation of how Rauner’s administration handled the Legionnaires’ crisis at the veterans’ home in Quincy.

The investigation includes whether residents, their families and staff were informed of the outbreak in a timely manner. Emails obtained by WBEZ Chicago show officials in Rauner’s office opted to hold off from making a public statement in 2015 even after more than a dozen people had become ill.

Rauner insisted there was no deliberate attempt to hide what was happening, saying “we took action immediately to protect our veterans.” He said his team needed to get all the facts and ensure there was “no panic or misinformation put out.”

He attacked Pritzker for ripping the toilets out of a home to get a $330,000 property tax break — a move the Cook County inspector general recently called a “scheme to defraud taxpayers.” Rauner said it was corrupt and “may involve criminal behavior.”

“This is the fundamental self-dealing that’s rotted our state at its core,” Rauner said.

Pritzker said he’s repaying the money and that the confidential report was leaked for political purposes.

Rauner also worked to distinguish his wealth and background from Pritzker’s, noting several times that the Democrat inherited his fortune, while he was a “middle-class kid” who worked his way through school and built his own wealth.

“He is trying to buy political office,” Rauner said. “He’s trying to buy the governorship to be something for the first time in his life because if he wasn’t a trust fund baby, he would be nothing.”

Pritzker noted Rauner swamped Democratic Gov. Pat Quinn in campaign spending during their 2014 race, spending millions of his personal fortune to help him win in a state that typically elects Democrats to statewide office.

Rauner has put more than $50 million into his campaign fund for the November election. Pritzker has given his campaign more than $146 million.

The Democrat said “it’s worth it” to wrest control of the state from Rauner, under whose leadership Illinois endured a roughly two-year state budget impasse that devastated social services and higher education, and almost led the state to a “junk” credit rating.

Rauner acknowledged he clashed with Democrats who lead the Legislature and was unable to achieve most of his pro-business agenda.

“It’s been hard,” he said. “I’m asking you to help me finish the job.”

Conservative Party candidate and state Sen. Sam McCann and Libertarian Grayson “Kash” Jackson also are on the November ballot but weren’t allowed to participate Wednesday because they didn’t reach a 10 percent polling threshold set by the debate hosts.

The debate was sponsored by ABC7, the Illinois League of Women Voters and Univision.